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arXiv · 2503.00947

Exploiting hidden singularity on the surface of the Poincar\'e sphere

Jinxing Li·Aloke Jana·Yueyi Yuan·Kuang Zhang·Shah Nawaz Burokur·Patrice Genevet
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Abstract

The classical Pancharatnam-Berry phase, a variant of the geometric phase, arises purely from the modulation of the polarization state of a light beam. Due to its dependence on polarization changes, it cannot be effectively utilized for wavefront shaping in systems that require maintaining a constant (co-polarized) polarization state. Here, we present a novel topologically protected phase modulation mechanism capable of achieving anti-symmetric full 2{\pi} phase shifts with near-unity efficiency for two orthogonal co-polarized channels. Compatible with -- but distinct from- - the dynamic phase, this approach exploits phase circulation around a hidden singularity on the surface of the Poincar\'e sphere. We validate this concept in the microwave regime through the implementation of multi-layer metasurfaces. This new phase modulation mechanism expands the design toolbox of flat optics for light modulation beyond conventional techniques.

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Jinxing Li, Aloke Jana, Yueyi Yuan, Kuang Zhang, Shah Nawaz Burokur, Patrice Genevet. 2025-03-02. Exploiting hidden singularity on the surface of the Poincar\'e sphere. https://arxiv.org/abs/2503.00947

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